This invention relates to a protective cover for sealing the inlet/outlet ports of a plastic bag, such as a blood bag or solution bag, used for medical patient infusions. The purpose of the protective cover is to seal the ports and maintain the contents as well as the ports sterile prior to their use.
When the plastic bag is being used, the protective cover is pulled apart in order to expose the port. The conventional type of blood bag, as described in U.S. Pat. No. 4,314,025, has two tabs provided at the edge of the protective cover. The cover can be pulled apart from each side by pulling the tabs along the welded line and then tearing the cover from the port.
Japanese Utility Model Publication No. 42634/77 discloses the method whereby the tab mounted on one side of the cover is welded to the protective cover. In addition, a V-shaped part is welded to the protective cover. When the cover is being removed by pulling on the tabs, it will readily tear in a "V" shape. This operation may be performed and completed with a single hand. Also, Japanese Utility Model Application Laid-Open Nos. 168332/83 and 100431/84 disclose that a tab welded to one side of the protective cover can be removed with a single hand so as to unseal the port.
The conventional plastic bag used for medical purposes is usually made up of two soft plastic sheets welded together along their peripheral edges. In order to prevent the sheets from sticking together, the surface of each sheet has been finely roughened. As a result of this treatment, the soft plastic sheets develop a cloudiness which makes it difficult to see through them and observe the contents of the bag.
Also, in the case of the conventional plastic cover openable with a single hand, the port can be viewed through the two plastic sheets, that is to say, the protective cover and the tab. The two sheets cause even more difficulty in observing the ports of the bag. Due to this condition, it is virtually impossible to detect a latent or obvious defect or abnormality which might exist in the port(s).